The parade of slow-moving diamondback terrapins began about 6:45 a.m. Wednesday.

Ron Marsico, spokesman for the Port Authority of New York and New Jersey, told 1010 WINS staff went out between takeoffs to remove the turtles. However, around 9:30 a.m. there were so many on Runway 4 Left and nearby taxiways that controllers were forced to move departing flights to another runway.

“We ceded to Mother Nature,” Marsico said.

The FAA says flight delays averaged about 30 minutes.

“I think the most significant threat is to the turtles themselves,” Marsico said. “For the safety of the turtles and not to impact flights our staff is out there along with the USDA working hard to get these turtles to where they need to be.”

The turtle migration happens every year at Kennedy. The airport is built on the edge of Jamaica Bay and a federally protected park. In late June or early July the turtles heave themselves out of the bay and head toward a beach to lay their eggs during mating season.

The peak of the migration usually lasts a few days, Marsico said.

Several pilots, some of them stifling chuckles, began reporting turtles on runway 4L just as the morning rush hour was beginning at JFK, according to a radio recording posted on LiveATC.net, which streams and records air traffic radio feeds.

“Be advised 30 feet into the takeoff roll, left side of the centerline, there’s another turtle,” called the pilot of American Airlines Flight 1009, a Boeing 767 that had just taken off bound for the Dominican Republic.

“There’s another one on the runway?” asked the controller.

“Uh, well he WAS there,” the pilot said with a laugh.

American 663, a Boeing 737 headed to Fort Lauderdale, found its way to runway 4L blocked by three of the roving reptiles.

Wayward wildlife is a serious concern at JFK and nearby LaGuardia Airport, which both sit on shorelines populated by geese, turtles, frogs and other animals. In January 2009, a U.S. Airways plane bound for Charlotte, N.C., was forced to land in the Hudson River after it hit a flock of birds and lost power in both engines. All 155 passengers and crew members were rescued.

(TM and Copyright 2011 CBS Radio Inc. and its relevant subsidiaries. CBS RADIO and EYE Logo TM and Copyright 2011 CBS Broadcasting Inc. Used under license. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.)